Nov. 7 (Bloomberg) -- The following companies are having unusual price changes in U.S. trading. Stock symbols are in parentheses, and share prices are as of 2:15 p.m. in New York.

Homebuilders fell after the National Association of Realtors said fewer Americans signed contracts to buy previously owned homes in September. Lennar Corp. (LEN US) dropped 11 percent to $7.50. Centex Corp. (CTX US) declined 6.5 percent to $10.84. D.R. Horton Inc. (DHI US) slipped 8.5 percent to $6.70. Pulte Homes Inc. (PHM US) lost 6.5 percent to $10.10. Toll Brothers Inc. (TOL US) decreased 7.4 percent to $18.94.

Accuray Inc. (ARAY US) fell 13 percent to $5.21 and slumped 17 percent earlier for the biggest intraday loss since Jan. 31. The maker of radiation-surgery equipment said a second delay reporting quarterly earnings was caused by an internal probe into accounting ``improprieties.''

AES Corp. (AES US) climbed 23 percent to $8.12 for the biggest intraday gain since Oct. 13. The U.S. power producer with operations in more than two dozen countries was boosted to ``neutral'' from ``underperform'' by Merrill Lynch & Co.

American Insurance Group Inc. (AIG US) jumped 14 percent to $2.13 and earlier gained 19 percent for the biggest intraday increase in a week. The company, which must sell assets to repay its government loan, will reach agreement to sell its personal lines and an equipment insurance unit by the end of the year, Reuters reported, citing a person familiar with the matter.

AmeriCredit Corp. (ACF US) rose 13 percent to $6.18 and jumped 34 percent earlier for the biggest intraday gain since March 11. Fairholme Capital boosted its stake in the company, which lends to car buyers with blemished credit records, to 19.6 percent from 18.1 percent, according to a Securities and Exchange Commission filing.

AutoNation Inc. (AN US) climbed 16 percent to $6.68 and earlier surged 37 percent for the biggest intraday gain since Sept. 19. The largest publicly traded U.S. auto retailer was raised to ``neutral'' from ``sell'' by Goldman Sachs Group Inc., which said shares are more fairly valued now.

Avis Budget Group Inc. (CAR US) fell 16 percent to $1.62 and dropped 21 percent earlier for the biggest intraday slide in two weeks. The third-largest U.S. rental car company said it will report a pretax loss excluding some items in the fourth quarter as U.S. air travel slows, hurting airport auto rentals.

CB Richard Ellis Group Inc. (CBG US) rose 17 percent to $6.63 and rallied 37 percent earlier for the biggest intraday gain since Oct. 10. The largest commercial real estate broker said third-quarter profit excluding items was 27 cents a share. That exceeded the average analyst estimate by 16 percent, according to a Bloomberg survey.

Delta Petroleum Corp. (DPTR US) tumbled 33 percent to $4.49 and dropped 42 percent earlier for the biggest retreat since July 2002. Kirk Kerkorian's Tracinda Corp. said it won't proceed with plans to expand its stake in the unprofitable Colorado oil and natural-gas producer. Deutsche Bank AG cut the stock's rating to ``sell'' from ``hold.''

Fidelity National Financial Inc. (FNF US) advanced 25 percent to $10.43 and surged 33 percent earlier for the biggest intraday gain since at least October 2005. The second-biggest U.S. title insurer will buy No. 3 LandAmerica Financial Group Inc. (LFG US) for about $128 million to cut costs as the industry struggles with the housing slump.

LandAmerica soared 85 percent to $8.80. First American Corp. (FAF US), the largest title insurer, rose 17 percent to $22.76.

Fluor Corp. (FLR US) rose 23 percent to $41.71 and earlier climbed 29 percent for the biggest intraday gain since December 2000. The largest publicly traded U.S. engineering firm said third-quarter profit climbed 95 percent, beating analysts' average estimate, as it won contracts to modernize a refinery in Indiana and help design a solar-panel plant in Singapore.

Fuel Systems Solutions Inc. (FSYS US) increased 40 percent to $37.46 and rallied 45 percent earlier for the biggest jump since October 2002. The company whose devices allow internal- combustion engines to run on alternative fuels increased its full-year revenue forecast to $385 million. That surpasses the average analyst estimate by 4.3 percent, according to Bloomberg data.

General Motors Corp. (GM US) fell the most in the Dow Jones Industrial Average, losing 12 percent to $4.23. The largest automaker said it may not have enough cash to keep operating this year and will fall ``significantly short'' of the amount needed by the end of June unless the auto market improves or it raises more capital. The company posted a third-quarter operating loss of $7.35 a share, wider than the average estimate of $3.94, according to a Bloomberg survey.

Genworth Financial Inc. (GNW US) fell the most in the S&P 500, losing 43 percent to $2.66. The insurer spun off by General Electric Co. (GE US) reported a third-quarter loss and suspended its dividend as the housing slump spurred an increase in mortgage-insurance claims and hurt investments.

Knot Inc. (KNOT US) surged 29 percent to $6.96 and earlier gained 39 percent for the biggest intraday jump since August 2002. The owner of Web sites and magazines for weddings reported profit before one-time items that was 78 percent more than analysts estimated, according to Bloomberg data.

Las Vegas Sands Corp. (LVS US) fell for a fifth day, losing 13 percent to $6.84. Sheldon Adelson, the billionaire who controls the casino, is in talks with Singapore's government and banks in Hong Kong and Macau as a cash shortage threatens $16 billion of casino developments in Asia, people with knowledge with the negotiations said.

Other casino owners slumped. MGM Mirage (MGM US) lost 9.8 percent to $12. Wynn Resorts Ltd. (WYNN US) declined 2.8 percent to $44.40.

Nvidia Corp. (NVDA US) rose 15 percent to $8.80 and earlier climbed 19 percent for the biggest intraday jump since November 2004. The second-largest maker of computer-graphics chips reported third-quarter profit and revenue that beat analysts' estimates after job cuts and a new contract with Apple Inc. (AAPL US) helped cushion the impact of the economic slowdown.

OSI Pharmaceuticals Inc. (OSIP US) gained 14 percent to $40.44 and jumped 18 percent earlier for the biggest intraday advance since December 2004. A study found that the drug Tarceva helped slow the progress of lung cancer when given immediately after chemotherapy. OSI markets the drug in the U.S.

Priceline.com Inc. (PCLN US) advanced 18 percent to $55.33 and jumped 22 percent earlier for the biggest intraday gain in a year. The Internet travel agency reported profit excluding some items of $2.39 a share in the third quarter. That beat the average analyst estimate by 15 percent, according to Bloomberg data.

Qualcomm Inc. (QCOM US) added 9.2 percent to $36.08. Investors are predicting earnings growth can't get any worse for the biggest maker of mobile-phone chips, said Mark McKechnie, an analyst at American Technology Research. Revenue this quarter may fall as much as 6 percent from a year earlier, the first decline in seven years, Qualcomm said yesterday.

Sprint Nextel Corp. (S US) lost 12 percent to $3.21 and fell earlier to $3.12, the lowest level since Oct. 28. The third- largest U.S. mobile-phone company reported a fourth straight loss as its customers switched to rival carriers. The company renegotiated its credit agreements to avoid the risk of default.

VeriSign Inc. (VRSN US) gained 8.1 percent to $21.13. The biggest operator of computers that direct Internet traffic reported operating margin of 35.5 percent in the third quarter, beating its own forecast, according to Jefferies Group Inc., which estimated 33.5 percent.

Windstream Corp. (WIN US) climbed 8.8 percent to $8.57. The phone company serving rural areas in 16 states reported customers defected at a slower pace last quarter.

Yahoo! Inc. (YHOO US) slid 13 percent to $12.10 and earlier slumped 17 percent for the biggest retreat in six months. Microsoft Corp. (MSFT US) said it is still not interested in acquiring the second-biggest U.S. seller of online advertisements after Yahoo Chief Executive Officer Jerry Yang said the Internet company is willing to sell. Microsoft added 2.2 percent to $21.34.

To contact the reporter on this story: Lu Wang in New York at lwang8@bloomberg.net

Last Updated: November 7, 2008 14:30 EST